Information and Advisory Note Number 30 Back to menu
1.1 This information note focuses on habitats occurring within the series of
Scottish SSSI notified for their biological interest. This series comprises
1,059 sites and covers 827,000 hectares, representing 10.5% of the land surface
of Scotland. Sites which are purely of earth science interest are excluded from
the analysis.
1.2 The purpose- of this note is to show
a) the extent and distribution of each main habitat type
b) the safeguard of these habitats by formal land management agreements between
SNH and land managers.
c) the pressures on these habitats arising from threats and damage
2 1 Data have been derived mostly from the Core data SSSI information system as held at
31 March 1995. The habitat data used in this
analysis have been collated from two principal
survey programmes conducted mostly in the
1980s
1. Phase 1 surveys of lowland habitats on SSSI
2. Upland survey data recorded by the Nature Conservancy Council's Upland Survey
Team
2.2 The upland survey data are based on a different classification system to that
used for lowland habitats. These data have recently been converted to Phase 1
equivalents by Uplands and Peatlands Branch However it was only possible to
define these Phase 1 data at the broadest level (woodland, grassland, heathland,
bog, fen, open water, coastland and rock). With the addition of these new data,
quantitative habitat data are now available for more than 90% of the SSSI
series.
2.3 This analysis does not distinguish between qualifying and non-qualifying
habitats (i.e. those which form part of the reasons for SSSI notification).
2.4 The 12 local authority regional boundaries in existence prior to
reorganisation in April 1996 have been used in this analysis because they
illustrate geographical variations more succinctly than the 32 new unitary
authority boundaries.
2.5 Where SSSI cross local authority boundaries, extents of management agreements
and habitats are not available for each local authority. In such cases the data
are allocated entirely to the local authority which holds the largest portion of
the SSSI
2.6 Habitat extents are available for 85% of the area subject to Management
Agreements However in most cases, the entire area has been allocated to the most
extensive (i.e. primary) habitat covered by the agreement.
3.1 Habitat extents are shown below in Figure 1 for each of the broad Phase 1 categories. The total area of unknown/unclassified habitat type (7% of the series) has been assigned pro-rata to each of the habitat types.
3.2 Heath and bog make up more than 60% of the SSSI series with most of this
comprising either blanket bog or upland heath
3.3 The coastal extent may be an overestimate because the SSSI area estimates used
to calculate extents often include areas below the low water mark (These should
be classed as marine, though technically they are not part of the SSSI series
because the SSSI legislation does not extend below the low water mark).
3 4 These figures are not directly comparable with data from the wider
countryside because Phase 1 coverage is incomplete outwith SSSI. However, some
comparisons are possible with data from the Land Cover Survey (1988) given
certain assumptions as shown at table 1
3 5 The above figures need to be treated with some caution because of the
difficulties in making comparisons between the two classification systems
3.6 SSSI habitats are not evenly distributed throughout Scotland and are
clustered in certain regions as shown at table 2 below. Extents in table 2 are
expressed in terms of the proportion of the entire area of each Local Authority
Region covered by each SSSI habitat. Please note that this table does not show
the extent of the total resource for each habitat, merely that which falls
within the SSSI series.
3.7 The above table demonstrates the concentration of SSSI quality heathland and bog in Highland Region and the Northern Isles. Coastland predominates in lowland regions such as Lothian, Fife and Dumfries and Galloway. Woodland is far less extensive than the aforementioned habitats and is especially sparse in the Northern Isles, the Western Isles and Southern Scotland.
4 1 The main site safeguard instruments available to SNH to supplement the
provisions of Section 28 of the Wildlife and Countryside Act 1981 are as follows
1. National Nature Reserves (including purchases, leases and Nature Reserve
Agreements)
2. Compensatory management agreements under Section 15 of the 1968 Countryside
Act (i.e. arising from a Notice of Intent to undertake a Potentially Damaging
Operation)
3. Positive, or voluntary Section15 agreements to maintain or enhance existing
site management.
The extent of each of the above mechanisms has been estimated in terms of the
proportion of the overall SSSI area. (Table 3)
4.2 Nearly 30% of the Grampian SSSI series is also declared as NNR (Some of the
largest NNR in Scotland including the Cairngorms, Glen Tanar, Muir of Dinnet and
Forvie are located here).
4 3 The Northern Islands have the highest proportion of SSSI under compensatory
agreement This is due mainly to grazing restrictions on heathlands.
4.4 This table shows that the safeguard of more than 70% of the Scottish SSSI
series is primarily dependent on the voluntary principle The voluntary principle is
also important on much of the land covered by formal site safeguard mechanisms,
especially since most management agreements do not guarantee complete protection
against all potentially damaging operations.
4.5 The combined area of Positive agreements is more than twice that of
compensatory agreements. However this does not take into account the fact that
many compensatory agreements also have positive elements built into them.
4 6 The high proportion of Borders region covered by voluntary agreement is due
mainly to two extensive heathland agreements
5 1 Figure 2 shows the composition of the 110,000 hectares of biological SSSI
which are declared as NNR
5.2 Habitat composition of NNR is similar to that of SSSI as a whole (c.f
figures 1 and 2), with heath and bog together constituting more than 60% of the
series.
5.3 Figure 3 shows the composition of the 43,000 ha of biological SSSI which are
subject to 359 compensatory agreements
5.4 Strathclyde Region contributes the most to the woodland, coastland and
grassland totals, whilst heathland agreements are concentrated in the Northern
Isles 60% of the
area covered by bog agreements occurs within Highland.
5 5 Figure 4 shows the composition of the 90,000 ha covered by 209 positive
agreements.
5.6 The extensive area of 'bog' in figure 4 is due almost entirely to the Peatland Management Scheme in Caithness and Sutherland (Highland Region).
Woodland agreements are also concentrated in Highland Region, and mostly involve
the erection of fences to exclude grazing animals.
5.7 The proportion of each SSSI habitat covered by S 15 management agreement is
shown at figure 5 below.
5.8 Compensatory agreements are fairly evenly distributed throughout the habitat
types, though they are rarely concluded over rock and open water.
5.9 Voluntary agreements by contrast are concentrated heavily on bog and woodland
due mainly to extensive agreements in Highland Region
5.10 Figure 6 shows the proportion of each
SSSI habitat covered either by S 15
agreement or by NNR.
6 1 This report assesses threats and damage to the SSSI series, i.e. those
'agents of change' which may have an adverse impact on the favourable condition
of the features within the series.
6.2 This report concentrates on pressures to SSSIs; a more strategic picture of
habitat change can be obtained from the National Countryside Monitoring Scheme
which provides estimates of change for each local authority.
6.3 There are two main indicators of pressure used in this analysis.
1. Total costs (cumulative annual and lump sums) paid out since 1981 as
compensation for net profit foregone. These payments follow a notice of intent
to undertake a potentially damaging operation It is assumed that
pressure can be expressed in terms of total costs per hectare.
2. Cases of acute damage recorded by the Loss and Damage reporting system since
recording began in 1986. (This system does not report cases of less
abrupt/chronic damage such as that caused by overgrazing and eutrophication)
6 4 These measures have been chosen for the following reasons
1 availability of data for the whole of Scotland within the Core data system
2 they can easily be quantified
3. there is considerable public interest in Management Agreements and SSSI
damage
6 5 These indicators are however, far from comprehensive in that they do not
take into account pressures from
7 1 The cumulative annual and capital costs of compensatory management
agreements since the Wildlife and Countryside Act 1981 are approximately £15
million. This sum only includes compensation for net profit foregone, and
excludes the cost of positive management works which are often a part of
compensatory agreements.
7.2 Compensatory agreements can be divided into a number of categories based on
the type of notice of intent to undertake a damaging operation (Table 4)
7.3 Nearly 50% of the compensatory agreements are agricultural Forestry related
claims are also significant though the pressures from afforestation claims has
recently eased due to a change in Government policy.
7.4 The scope for further analysis of the above categories is rather limited
because it is not possible to apportion costs or extents
7.5 Figure 7 shows the proportion of the £15m spent on safeguarding each habitat
About 15% of the total expenditure relates to a mixture of habitats; these costs
have been apportioned pro rata to each habitat type.
7.6 Figure 8 shows the total cumulative cost for each habitat divided by the
total hectarage of each SSSI habitat. This gives a crude measure of 'pressure'
on each habitat arising from compensatory claims
7.7 This indicates that pressures may be most intense on woodland habitats, with
about 60% of the threats arising from proposed forestry operations. About 75% of
grassland and heathland cases are agriculturally related, whilst more than 50% of
cases on bogs involve proposals for afforestation Open water and rock habitats
are under the least pressure from compensatory claims, reflecting their low
potential for agricultural and forestry development.
8 1 All cases exceeding the SNH annual reporting thresholds from 1986 to 1995
were used in this analysis. This includes 246 cases of acute or abrupt damage
above 0.5 hectares or where more than 10% of a habitat or species have been
affected. To put this in context, this represents less than 0 1% of the total
Biological SSSI series by area. Damage may arise from either an owner, occupier,
statutory undertaker or third party.
8.2 A scoring system was devised to record the impact of each incident, based on
the extent of damage and whether or not recovery was likely within 15 years
Details of the scoring system are given at Table 5
8.3 Figure 9 below shows the total seventy scores for each habitat. Where there
is more than one habitat involved in an incident the severity score for that
incident has been divided by the number of damaged habitats.
8.4 It is apparent from figure 9 that SSSI damage is concentrated on certain
habitats such as woodland, grassland and coastland.
8.5 The pattern in figure 9 is clearly different to that shown at figure 1.
Heathland and bog (the two most extensive SSSI habitats) are less severely
affected than the aforementioned habitats. It is also interesting to note that
the value for fen in figure 9 (6.5%) is higher than the equivalent value at
figure 1 (0.8%), thereby suggesting that fen is especially susceptible to
damage.
8.6 Damage cases can be categorised
according to types of damaging activities as
shown at figure 10 below.
8.7 Burning is the most widespread single activity and accounts for 18% of the
total number of cases; these cases include muirburning, arson and accidental
fires.
8.8 It should be noted that because damage reporting only detects obvious/abrupt
changes, the impact of certain factors such as grazing and pollution are likely
to underestimated.
8.9 The type of land use is also recorded within the reporting system, though
there are a large proportion of cases (40%) where the land use is either
unrecorded or is not applicable because damage is perpetrated by a third party
Agricultural activities together account for more than 20% of all cases, and
forestry 10%.
9.1 This report represents the first analysis of the entire network of Scottish
biological SSSI in terms of their component habitats. Tentative conclusions have been made,
revealing a partially complete picture of the SSSI series.
9.2 It indicates that certain habitats (e.g. bog and woodland) are relatively
better protected by existing mechanisms than others such as grassland, rock and
coastland.
9 3 Pressures from both damaging operations and compensatory claims are greatest
on woodland and fen habitats Fens are restricted in distribution and are
vulnerable to drainage.
9.4 Coastland and grassland show remarkably similar patterns throughout the
analysis Both of these habitats are relatively highly affected by damaging
activities.
9.5 Rock habitats are mainly upland outcrops supporting some of Scotland's rarest
plants, which are susceptible to both recreation and grazing pressures These
pressures are unlikely to be registered by either of the indicators used in this
paper.
9.6 Similarly, these indicators may not record the main pressures on open waters
(recreational pressures and changes in water quality).
9.7 The analysis is inevitably constrained by the limited availability of data for
the whole of Scotland This situation is being addressed by a number of separate
initiatives which are itemised below.
9.8 A comparison of LCS data with digitised SSSI boundaries using Geographical
Information Systems (GIS)
9.9 The collation of inventories for the Natura
2000 network (a key subset of the SSSI series)
9.10 The production of SSSI Management. Statements (This process incorporates an
assessment of key features present on each site).
9.11 Data on management agreements and planning applications will be improved
following the implementation of new corporate information systems
9.12 SNH's ability to record SSSI damage will be greatly improved by the adoption
of a new system for SSSI condition monitoring This will enable assessments of
damage to be made against clear definitions of favourable condition.
Dargie, T C D, Briggs D J (1991) State of the Scottish Environment 1991. Scottish
Wildlife and Countryside Link.
Department of the Environment (1994) Digest of Environmental Protection and
Water Statistics No 16-1994 HMSO London
Macaulay Land Use Research Institute (1993) The Land Cover of Scotland 1988.
Aberdeen
Nature Conservancy Council (1990) Handbook for Phase 1 habitat survey NCC
Rowell, T A, (1992) SSSIs- A Health Check - a review of the statutory protection
afforded to sites of special scientific interest in Great Britain. Wildlife
Link.
Scottish Natural Heritage (1995) The Natural Heritage of Scotland: an overview.
SNH
Scottish Natural Heritage (1995) Annual Report 1994-95.
Scottish Office (1990) The Scottish Environment - Statistics. No 2 -1989.
Scottish Office, Edinburgh
Tudor G J, Mackey E C, Underwood FM, (1994) The National Countryside Monitoring
Scheme - Scottish Natural Heritage.
Dave Chambers, Designated Areas and Sites Branch,
Research and Advisory Services
Directorate (RASD),
Scottish Natural Heritage,
2 Anderson Place,
Edinburgh EH6 5NP
(0131 446-2445)
Lynne Farrell, Head of Designated Areas and Sites Branch, RASD Comments on draft
report
Julian Holbrook, Environmental Audit Branch. RASD Comments on draft report
Dave Horsfield, Uplands and Peatlands Branch, RASD Conversion of upland SSSI
data to Phase 1 habitat types